The present invention concerns a boomerang link for aircraft engine mounts.
It also concerns an engine mount including such a link, a propulsion system including such an engine mount, and an aircraft equipped with such a propulsion system,
Aircraft jet engines are usually attached to the wings or to the fuselage by means of a pylon to which the jet engine is connected by means of engine mounts and links for transmitting thrust forces.
FIG. 1 shows an example of a propulsion system 8 of the type designed to be attached laterally to an aircraft fuselage rear part. This propulsion system 8 includes a jet engine 10, for example of the open rotor pusher type, and a pylon 12, partially visible, to which the jet engine is connected. The rotors, the nacelle and the air intake of the jet engine 10 are not represented in FIG. 1, and so only the main structural casings of the jet engine can be seen. The jet engine 10 has a longitudinal axis 11.
The jet engine 10 is primarily attached to the pylon 12 by a forward engine mount 14, an aft engine mount 16, and two links 18 for transmitting thrust forces, of which only one can be seen in FIG. 1.
FIG. 2 shows to a larger scale the forward engine mount 14 and the connection of the links 18 to a rigid structure of the pylon 12.
The forward engine mount 14 includes a fitting 20 fixed to the pylon 12 and forming a support structure to which are connected a link 22 and a boomerang link 24. The link 22 is articulated to the fitting 20 by means of a first pivot and is designed to he articulated to the jet engine 10 by means of a second pivot. The boomerang link 24 is connected to the fitting 20 by means of two pivots and is designed to be articulated to the jet engine 10 by means of a third pivot. The pivots of the link 22 and of the boomerang link 24 are parallel to the longitudinal axis 11 of the jet engine that can be seen in FIG. 1. Finally, each of the links 18 for transmitting thrust forces is articulated to a swing-arm 26 that is itself connected to the fitting 20 by means of two pivots. The pivots of the components described above are not shown in FIG. 2 for reasons of clarity.
It should he noted that the aforementioned pivots may each incorporate a ball joint in order to impart more freedom of movement to the articulated components and to reduce unwanted moments, in a manner that is well known in itself.
A particular function of the boomerang link 24 is to take forces oriented transversely relative to the longitudinal axis of the jet engine as well as to take the engine torque about the aforementioned longitudinal axis.
However, the connection of the jet engine 10 to the pylon 12 by means of the components described above leads to transmission of vibrations from the jet engine to the pylon 12.
This is particularly problematic in the case of propulsion systems attached to the fuselage of the aircraft, as described above, because the vibrations are then transmitted directly to the structure of the fuselage. These vibrations are therefore liable to increase the wear of the structure of the fuselage and to reduce the comfort of passengers.
Propulsion systems mounted above or below the wings of the aircraft generally include a configuration of engine mounts and links for transmitting thrust forces analogous to that described above.
In these latter propulsion systems, vibrations induced by the jet engines are in theory damped by the flexibility of the wings.
However, if the intensity of these vibrations is particularly high, notably in the event of a malfunction of a jet engine, there is also a risk of the vibrations of the latter being transmitted to the structure of the fuselage of the aircraft.